July 8th, 2013
Selections from Richard Lehman’s Literature Review: July 8th
CardioExchange is pleased to reprint selections from Dr. Richard Lehman’s weekly journal review blog at BMJ.com. Selected summaries are relevant to our audience, but we encourage members to engage with the entire blog.
JAMA 3 July 2013 Vol 310
Effect of Home BP Telemonitoring and Pharmacist Management on BP Control (pg. 46): If you identify people with poorly controlled blood pressure in primary care and introduce a system of intensive telemonitoring run by pharmacists according to a strict protocol, you are bound to get better BP control than if you leave it to “usual care.” But for each individual, the value of BP control will differ, as it does with every risk factor, and so will the adverse effects of treatment. You don’t need a doctor to measure BP but you do need someone in thoughtful dialogue with the patient to determine what the marginal value of further intensification might be. The simple “better control” trial described here didn’t really need to be done: anyone can intensify BP control, but the real question is whether such intensification is really worthwhile for the patients given their overall risk and personal preferences, and that goes well beyond a simple surrogate like BP.
Home-Based Walking Exercise Intervention in Peripheral Artery Disease (pg. 57): Again, if you take a group of people with peripheral artery disease and advise them to walk regularly, some will and some won’t; if you enroll them in weekly classes where they spend 45 minutes walking around and a further 45 being told how good it is for them to do this every day then you are bound to get better results. And again I puzzle as to whether this will work in real life: but it may well be worth a try, because in this case the patients are likely to notice a direct improvement in function.
Natriuretic Peptide-Based Screening and Collaborative Care for Heart Failure (pg. 66): In 2001 I proposed a study in which we would screen individuals with risk factors for heart failure to see if they had elevated BNP and treat them to reduce it. The MRC liked the idea and we did a pilot study, but found that BNP was too labile a marker to guide individual treatment decisions. The Irish team who report their similar study here achieved better success through a less ambitious protocol: starting in 2005, they cluster-randomised GP practices to screening for BNP or none: in the intervention practices they subjected the patients with high BNP to more intensive work-up and treatment and found that this somewhat reduced cardiovascular events and hospital admissions over 4 years. This trial raises more questions than it answers, but to deal with them would take a small book.
NEJM 4 July 2013 Vol 369
Clopidogrel with Aspirin in Acute Minor Stroke or Transient Ischemic Attack (pg. 11): A big Chinese trial establishes that in the population studied, adding clopidogrel to aspirin following a transient ischaemic attack or minor ischaemic stroke reduces the risk of a further stroke within 90 days, and does not carry a significant risk of major bleeding or haemorrhagic stroke. It looks like a well-conducted trial but the editorial poses some good questions about its generalisability to other populations. More big trials elsewhere, please.
BMJ 6 July 2013 Vol 347
When a Test Is Too Good: Pulmonary embolism is easily missed, and it appears in the BMJ series of that name. Pulmonary embolism is also easily overdiagnosed, and it appears in the first BMJ article in a new series called Too Much Medicine. It’s a question of balance: the lungs are meant to act as a sieve as well as an organ of oxygenation, and CT angiography may be making us aware of lots of debris that really doesn’t matter. Lifelong anticoagulation should not be embarked upon lightly. This is a cracking first article co-written by friends. For a contrasting patient’s perspective, go to John Launer’s beautiful piece in QJM.